MULTIPLE DISC GRINDING MACHINE, IN PARTICULAR FOR PROCESSING STONE AND LIKE MATERIALS

Description

Technical filed

[0001] The present invention relates to a machine having the features set out in the preamble of claim 1.

Technological background

[0002] The invention is for use in particular in the sector of the processing of stone and like materials, in which use is made of multiple disc grinding machines having a plurality of cutting discs with abrasive segments combined in a pack on a shaft which may be caused to rotate. When using multiple disc grinding machines of the above-mentioned type, use is typically made of coolant fluids which are conveyed to the processing zones to ensure that the heat generated by processing, following contact between the abrasive sectors and the surfaces of the workpiece, is adequately dissipated. In known solutions the shaft is provided with an internal hole in order to convey the fluid to a distributor member, for instance a bushing interposed between the shaft and the discs and designed to collect the fluid and distribute it to the exterior of the discs in the processing zones. This solution nevertheless requires the provision of a specific distributor member which has to be mounted when the cutting discs are being mounted on the multiple disc grinding machine.

[0003] The closest prior art BE 669 045 discloses the preamble of claim 1.

Description of the invention

[0004] A main object of the invention is to provide an abrasive disc for multiple disc grinding machines designed to provide a coolant distribution system which is structurally simpler and easier to use, but which continues to provide efficient cooling of the tool.

[0005] This object is achieved by the invention by means of a multiple disc grinding machine embodied in accordance with the accompanying claims.

Brief description of the drawings

[0006] Other advantages and features of the present invention will become clear from the following detailed description of a preferred embodiment thereof which is given with reference to the appended drawings which are provided purely by way of non-limiting example and in which:

• Fig. 1 is a perspective view of an abrasive disc for a multiple disc grinding machine according to the invention;
• Fig. 2 is a view in axial section of the disc of Fig. 1;
• Fig. 3 is a view in partial section of a multiple disc grinding machine equipped with abrasive discs according to the invention.

Preferred embodiments of the invention

[0007] With reference to the appended drawings, an abrasive disc for a multiple disc grinding machine embodied in accordance with the present invention is shown overall by 1. A grinding machine equipped with a plurality of abrasive discs closed in a pack on a driving shaft 3 of the grinding machine which may be caused to rotate about an axis X is shown by 2. Only the cutting disc 1 will be described in detail below, as the features described mirror those of the remaining discs of the pack mounted on the shaft 3.

[0008] The multiple disc grinding machine designed in this way is for particular use for the processing of stone and like materials but could be used in other fields, for instance for the processing of ceramics, refractory materials or glass.

[0009] The disc 1 comprises a disc-shaped support 1a which is axially symmetrical with a main axis shown by Y in the drawings and bears a circumferential rim 4 on which abrasive cutting sectors 5 are applied.

[0010] The transverse thickness of the disc at its central portion, measured parallel to the axis Y, is shown by 6.

[0011] The support 1a is also provided with a central hole 7 for connection to an end portion of the driving shaft 3 which causes the disc to rotate during cutting operations involving tangential contact between the rim 4 and the material to be processed.

[0012] The connection hole 7 has a first cylindrical through section 7a which comes into coupling contact with the driving shaft 3 and a second cylindrical through section 7b extending as an axial continuation of the first section, this second section having a diameter greater than the first section. As a result of this feature, an annular chamber shown by 8 is formed at the location of the second through section 7b, following connection with the shaft 3, whose function will be explained in detail in the following description. The sequence of through holes 7a, 7b extends through the entire transverse thickness 6 of the disc, so that the section 7b extends, with its free end, up to the location of a front transverse surface of the disc shown by 9. This surface extends with an annular configuration from the hole 7 in the direction of the rim 4 over a predetermined radial development. When the discs are mounted as a pack on the shaft 3, the surface 9 of each disc abuts against the adjacent disc and as a result of the axial clamping action of the pack of discs, this surface acts as a friction member designed to prevent the relative sliding of adjacent discs.

[0013] The front surface 9 is provided with at least one radial recess, shown by 10, which extends from the annular chamber 8 in the direction of the rim 4 radially including the whole surface. A preferred choice, shown in the appended drawings, is to provide three recesses 10 angularly spaced from one another at regular intervals (with an angular pitch of 120°), although the invention could function with other configurations. The recesses 10 may also be readily provided on the front surface 9 by respective radial milling operations on the surface 9. As is clearly shown in Fig. 3, once the discs are positioned as a pack on the shaft 3, the annular chamber 8 is connected in fluid communication with each of the recesses 10 so as to ensure a passage for a coolant fluid accumulated in the chamber and conveyed to the exterior of the disc via the recess 10.

[0014] The driving shaft of the grinding machine 2 is provided with an internal axial duct 11 for supplying the coolant fluid, which duct is continued by one or a plurality of radial end ducts 12 opening at the location of cylindrical shell of the end portion of the shaft 3 designed to house the abrasive discs.

[0015] The thickness 6 of the disc 1 in contact with the shaft is smaller than the diameter of the hole 12 provided on the shaft, so as to ensure a passage for the coolant fluid from the chamber 8 containing the fluid to the recesses 10, which recesses 10 therefore form a kind of channel for supplying the fluid to the exterior of the disc in order to distribute the fluid to the processing zones close to the abrasive sectors of the circumferential rim 4.

[0016] The provision of the annular chamber 8 in fluid connection with the recesses 10 therefore makes it possible for the coolant fluid to be accumulated in the chamber and then to flow radially, under the centrifugal effect of the rotation of the grinding machine, along the recesses so as efficiently to reach the processing zone of the abrasive sectors of the discs and thus to ensure the cooling of the surfaces in relative contact of the discs and the material being processed.

[0017] In a variant of the invention the cylindrical shell of the driving shaft 3 intended to receive the cutting discs, may be provided with a groove 13 (or a plurality of grooves 13) extending axially along the whole pack of discs and in fluid communication with the supply holes 12 of the coolant fluid. This groove may improve the distribution effect of the coolant fluid to each annular chamber of the discs mounted in a pack on the shaft, as shown in Fig. 3, in the lower axial section of the grinding machine.

[0018] The invention thus achieves the objects set out above and provides many advantages over known solutions.

[0019] A main advantage lies in the simpler structure and operation of the cooling system which the invention applies to multiple disc cooling systems, avoiding the use of specific distribution members for the coolant fluid, such as the bushings or like distributors for which known solutions make provision. This simpler structure is advantageously reflected by easier use, especially as regards operations to mount the pack of discs on the grinding machine and remove it therefrom, a major advantage when taking account of the fact that these tools have to be readily and rapidly interchangeable as a result of the wear of the abrasive profiles to which they are subject when processing materials.

Claims

1. A multiple disc grinding machine comprising

- a driving shaft (3),

- a plurality of abrasive discs (1) combined in a pack on said shaft (3), each of said discs comprising a disc-shaped support (1a) having a circumferential rim (4) on which abrasive cutting sectors (5) are applied and an opposing central hole (7) for fitting on to the driving shaft (3) of the grinding machine, said hole (7) extending through the thickness of the disc-shaped support (1a), and the hole (7) has a first cylindrical through section (7a) which comes into coupling contact with the driving shaft (3),

- at least one radial recess (10) is formed on a front surface (9) of the disc-shaped support (1a),

- the driving shaft (3) is provided with an internal axial duct (11) for supplying the coolant fluid, said duct (11) being continued by at least one radial end hole (12) opening at the location of the cylindrical shell of the end portion of the shaft (3) designed to house the abrasive discs, the thickness (6) of the disc (1) in contact with the shaft (3) and the radial end hole (12) being smaller than the diameter of the radial end hole (12) provided on the shaft ;

the machine being characterised in that

- a portion of said central hole (7) has a diameter greater than the diameter of the connection to said shaft (3), such that an annular chamber (8) is formed in the thickness of the support, and wherein

- the central hole (7) has a second cylindrical through section (7b) extending as an axial continuation of the first section (7a), said second section (7b) having the diameter greater than the first section (7a), such that said annular chamber (8) is formed at the location of the second through section (7b), following connection with the shaft (3),

- the at least one radial recess (10) is extending from said annular chamber (8) towards the circumferential rim (4) of said disc, in such a way that a coolant fluid fed into the driving shaft (3) can accumulate in said annular chamber (8) and can then flow through said radial recess (10) towards the abrasive edge of said disc, and wherein

- the front surface (9) of each of said abrasive discs in said pack abuts against a corresponding surface of the adjacent abrasive disc, and wherein axial clamping action of the pack of the abrasive discs causes said surfaces to act as friction members which prevent relative sliding of adjacent ones of the abrasive discs, and wherein

a passage for the coolant fluid from the chamber (8) containing the fluid to the recesses (10) is ensured, said recesses (10) therefore forming a kind of channel for supplying the fluid to the exterior of the disc in order to distribute the fluid to the processing zones close to the abrasive sectors (5) of the circumferential rim (4).

2. A multiple disc grinding machine according to claim 1, wherein the driving shaft includes at least a groove (13) extending axially in the cylindrical shell of the end of the driving shaft intended to be connected to said discs, said at least one groove (13) communicating with said radial end hole (12) for the feed of the coolant fluid and being capable of bringing said radial end hole (12) into communication with the annular chamber (8) of the corresponding discs (1), which are fixed in a pack on the driving shaft (3), the groove (13) improving the distribution effect of the coolant fluid to each annular chamber (8) of the discs mounted in a pack on the driving shaft.

Ansprüche

1. Mehrscheibenschleifmaschine, umfassend:

- eine Antriebswelle (3),

- eine Mehrzahl von Schleifscheiben (1), die in einer Packung auf der Welle (3) kombiniert sind, wobei jede der Scheiben einen scheibenförmigen Träger (1a) mit einem umlaufenden Rand (4), auf dem abrasive Schneidabschnitte (5) aufgebracht sind, und mit einem gegenüberliegenden zentralen Loch (7) zum Aufstecken auf die Antriebswelle (3) der Schleifmaschine aufweist, wobei sich das Loch (7) durch die Dicke des scheibenförmigen Trägers (1a) erstreckt und das Loch (7) einen ersten zylindrischen Durchgangsabschnitt (7a) aufweist, der mit der Antriebswelle (3) in Kopplungskontakt kommt,

- wobei zumindest eine radiale Aussparung (10) an einer Stirnfläche (9) des scheibenförmigen Trägers (1a) ausgebildet ist,

- wobei die Antriebswelle (3) mit einem inneren axialen Kanal (11) zum Zuführen des Kühlfluids versehen ist, wobei der Kanal (11) durch zumindest ein radiales Endloch (12) fortgeführt wird, das sich an der Stelle des zylindrischen Mantels des Endbereichs der Welle (3) zum Aufnehmen der Schleifscheiben öffnet, wobei die Dicke (6) der Scheibe (1), die mit der Welle (3) und dem radialen Endloch (12) in Kontakt ist, kleiner als der Durchmesser des radialen Endlochs (12) ist, das an der Welle vorgesehen ist;

- wobei die Maschine dadurch gekennzeichnet ist, dass

- ein Bereich des zentralen Lochs (7) einen Durchmesser aufweist, der größer als der Durchmesser der Verbindung mit der Welle (3) ist, so dass eine Ringkammer (8) in der Dicke des Trägers ausgebildet wird, und wobei

- das zentrale Loch (7) einen zweiten zylindrischen Durchgangsabschnitt (7b) aufweist, der sich als axiale Fortführung des ersten Abschnitts (7a) erstreckt, wobei der zweite Abschnitt (7b) einen Durchmesser aufweist, der größer als der des ersten Abschnitts (7a) ist, so dass die Ringkammer (8) an der Stelle des zweiten Durchgangsabschnitts (7b) ausgebildet wird, der einer Verbindung mit der Welle (3) folgt,

- das sich die zumindest eine radiale Aussparung (10) von der Ringkammer (8) in Richtung des Umfangsrands (4) der Scheibe derart erstreckt, dass sich ein Kühlfluid, das der Antriebswelle (3) zugeführt wird, in der Ringkammer (8) ansammeln und dann durch die radiale Aussparung (10) in Richtung der Schleifkante der Scheibe fließen kann, und wobei

- die Stirnfläche (9) von jeder der Schleifscheiben in der Packung an einer entsprechenden Oberfläche der benachbarten Schleifscheibe anliegt, und wobei eine axiale Klemmung der Packung der Schleifscheiben bewirkt, dass die Oberflächen als Reibelemente wirken, die ein relatives Gleiten von benachbarten Scheiben der Schleifscheiben verhindern, und wobei

- ein Durchgang für das Kühlfluid aus der Kammer (8), die das Fluid enthält, zu den Aussparungen (10) gewährleistet ist, wobei die Aussparungen (10) daher eine Art von Kanal zum Zuführen des Fluids zur Außenseite der Scheibe bilden, um das Fluid an die Bearbeitungszonen in der Nähe der Schleifabschnitte des umlaufenden Rands (4) zu verteilen.

2. Mehrscheibenschleifmaschine nach Anspruch 1, wobei die Antriebswelle zumindest eine Nut (13) umfasst, die sich axial im Zylindermantel des Endes der Antriebswelle erstreckt, die mit den Scheiben verbunden werden soll, wobei zumindest eine Nut (13) mit dem radialen Endloch (12) zum Zuführen des Kühlfluids in Verbindung ist, und in der Lage ist, das radiale Endloch (12) in eine Verbindung mit der Ringkammer (8) der entsprechenden Scheiben (1) zu bringen, die in einer Packung auf der Antriebswelle (3) fixiert sind, wobei die Nut (13) die Verteilungswirkung des Kühlfluids zu jeder Ringkammer (8) der Scheiben verbessert, die in einer Packung an der Antriebswelle befestigt sind.

Revendications

1. Machine de meulage à disques multiples comprenant

- un arbre d'entraînement (3),

- une pluralité de disques abrasifs (1) combinés dans un empilement sur ledit arbre (3), chacun desdits disques comprenant un support discoïde (1a) comportant une bordure circonférentielle (4) sur laquelle des secteurs de coupe abrasifs (5) sont appliqués et un trou central opposé (7) pour l'ajustement sur l'arbre d'entraînement (3) de la machine de meulage, ledit trou (7) s'étendant sur toute l'épaisseur du support discoïde (1a), et le trou (7) comporte une première section traversante cylindrique (7a) qui vient en contact d'accouplement avec l'arbre d'entraînement (3),

- au moins un évidement radial (10) est formé sur une surface avant (9) du support discoïde (1a),

- l'arbre d'entraînement (3) est doté d'un conduit axial interne (11) pour l'alimentation en fluide de refroidissement, ledit conduit (11) étant prolongé par au moins un trou radial d'extrémité (12) débouchant à l'endroit de l'enveloppe cylindrique de la partie d'extrémité de l'arbre (3) conçu pour accueillir les disques abrasifs, l'épaisseur (6) du disque (1) en contact avec l'arbre (3) et le trou radial d'extrémité (12) étant inférieure au diamètre du trou radial d'extrémité (12) prévu sur l'arbre ;

la machine étant caractérisée en ce que

- une partie dudit trou central (7) a un diamètre supérieur au diamètre du raccordement audit arbre (3), de telle manière qu'une chambre annulaire (8) est formée dans l'épaisseur du support, et dans laquelle

- le trou central (7) comporte une seconde section traversante cylindrique (7b) s'étendant sous la forme d'un prolongement axial de la première section (7a), ladite seconde section (7b) ayant le diamètre supérieur à la première section (7a), de telle manière que ladite chambre annulaire (8) est formée à l'endroit de la seconde section traversante (7b), après le raccordement à l'arbre (3),

- l'au moins un évidement radial (10) s'étend à partir de ladite chambre annulaire (8) vers la bordure circonférentielle (4) dudit disque, d'une manière telle qu'un fluide de refroidissement introduit dans l'arbre d'entraînement (3) peut s'accumuler dans ladite chambre annulaire (8) et peut ensuite s'écouler à travers ledit évidement radial (10) vers le bord abrasif dudit disque, et
dans laquelle

- la surface avant (9) de chacun desdits disques abrasifs dans ledit empilement vient en butée contre une surface correspondante du disque abrasif adjacent, et dans laquelle l'action de serrage axial de l'empilement des disques abrasifs amène lesdites surfaces à agir comme des éléments de frottement qui empêchent le glissement relatif de certains adjacents parmi les disques abrasifs, et dans laquelle

un passage pour le fluide de refroidissement de la chambre (8) contenant le fluide aux évidements (10) est assuré, lesdits évidements (10) formant ainsi une sorte de canal pour l'alimentation en fluide à l'extérieur du disque afin de distribuer le fluide dans les zones de traitement près des secteurs abrasifs (5) de la bordure circonférentielle (4).

2. Machine de meulage à disques multiples selon la revendication 1, dans laquelle l'arbre d'entraînement inclut au moins une rainure (13) s'étendant axialement dans l'enveloppe cylindrique de l'extrémité de l'arbre d'entraînement destinée à être raccordée auxdits disques, ladite au moins une rainure (13) communiquant avec ledit trou radial d'extrémité (12) pour l'introduction de fluide de refroidissement et étant capable d'amener ledit trou radial d'extrémité (12) en communication avec la chambre annulaire (8) des disques correspondants (1), qui sont fixés dans un empilement sur l'arbre d'entraînement (3), la rainure (13) améliorant l'effet de distribution du fluide de refroidissement dans chaque chambre annulaire (8) des disques montés dans un empilement sur l'arbre d'entraînement.

Drawing